The present invention relates to 4(3H)-oxobenzo-2,1,3-thiadiazine-2,2-dioxides, derivatives thereof and methods for controlling unwanted plants with said compounds.
It is known that 3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide and the salts thereof may be used as herbicide. See U.S. Pat. Nos. 3,708,277 and 3,621,017. Related compounds having pharmacological activities are also known. See, for example, U.S. Pat. Nos. 3,217,001 and 3,041,336. The 3-(1-methylethyl)-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide compound is known to be useful in selective weed control in corn, sorghum, cereals, rice and turf. However, the action of such compound has not been found to be satisfactory in the control of weeds in the presence of certain desired broadleaf crops, such as cotton, since the compound has been found to exert a significant phytotoxic effect on the desired crop plants at dosage levels required for effective and economical weed control.
It is therefore an object of the instant invention to provide new valuable 4(3H)-oxobenzo-2,1,3-thiadiazine-2,2-dioxides and methods for the use thereof in the control of unwanted plants with negligible effect on the desired crop plants.